A solar system is a smart, durable technology, but like any electrical system it is affected by its surroundings. One of the most common questions we get at Rotem Energy, from private and business clients alike, is:
do the solar panels need cleaning? And if so, how often?
So let us clear it up: what really matters about cleaning a solar system, how it affects efficiency, and what is worth doing to keep output high for years.
Why clean the panels at all?
Solar panels are usually installed on roofs exposed to sun, wind and rain. Over time the following build up on them:
- Dust, sand and soot (mainly in urban areas or near building sites).
- Bird droppings.
- Leaves and seasonal dirt.
- Airborne pollutants (in industrial areas, for example).
All of these create a layer of dirt that reduces the amount of sunlight reaching the photovoltaic cells, which can lower the system’s output.
How much difference does it really make?
In most cases the drop in output is very modest. Think of a window at home: when it is dusty, does sunlight still come through? It does. The change in the amount of energy produced is minor – around 1-2% at most.
Panels can be cleaned automatically by installing a cleaning system, which adds to the overall cost, or manually by a professional who goes up to the roof every so often during the summer (in winter the rain does the job). Each option carries its own cost.
How to clean properly
If you do decide to clean the system, it is worth doing it right. Rotem Energy does not provide cleaning services for solar systems, but we certainly give our clients full advice on keeping the system efficient over time. You will get all the relevant information about your system from us, whether it is commercial or residential.
General principles for cleaning properly:
- Use lukewarm water at low pressure. There is no need for pressure washers, which can damage the panels.
- Avoid harsh chemicals.
- Clean in the early morning or the evening, when the panels are cool.
- Use a soft cloth or squeegee, without aggressive scrubbing.
- Businesses with large systems should use a professional cleaning company that specialises in solar panels.
Keeping performance up starts with the right design
The best way to make sure a system keeps performing well for years is to install it properly in the first place.
At Rotem Energy we make a point of:
- Designing the ideal tilt angle – which helps rain wash the panels naturally.
- Positioning the system correctly – minimising shading and dirt from air-conditioning units, trees, neighbouring roofs and so on.
- Using quality equipment only – panels with anti-soiling coatings and partial self-cleaning.
- Briefing the client – including tips for keeping output high over time.
Our installations are carried out by our own certified, professional and highly experienced crew, so that our clients are satisfied and get the greatest benefit at the lowest possible cost.
We may not clean solar systems at Rotem Energy – but we do give our clients peace of mind, by installing the system to the most professional standard in Israel with our own experienced in-house crew, making the fullest possible use of the roof so that you get the maximum output from it.
You may also be interested in: small home solar systems | solar systems for business | the urban premium
